def position(self, hyperplane):
x = [Variable(i) for i in range(self.dim)]
p = C_Polyhedron(Generator_System(self.ppl))
s_rel = p.relation_with(
sum(hyperplane.a[i] * x[i] for i in range(self.dim)) + hyperplane.b < 0)
if s_rel.implies(Poly_Con_Relation.is_included()):
return -1
else:
b_rel = p.relation_with(
sum(hyperplane.a[i] * x[i] for i in range(self.dim)) + hyperplane.b > 0)
if b_rel.implies(Poly_Con_Relation.is_included()):
return 1
else:
return 0
def has_IP_property(self):
"""
Whether the lattice polytope has the IP property.
That is, the polytope is full-dimensional and the origin is a
interior point not on the boundary.
OUTPUT:
Boolean.
EXAMPLES::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: LatticePolytope_PPL((-1,-1),(0,1),(1,0)).has_IP_property()
True
sage: LatticePolytope_PPL((-1,-1),(1,1)).has_IP_property()
False
"""
origin = C_Polyhedron(point(0*Variable(self.space_dimension())))
is_included = Poly_Con_Relation.is_included()
saturates = Poly_Con_Relation.saturates()
for c in self.constraints():
rel = origin.relation_with(c)
if (not rel.implies(is_included)) or rel.implies(saturates):
return False
return True
def contains(self, point_coordinates):
r"""
Test whether point is contained in the polytope.
INPUT:
- ``point_coordinates`` -- a list/tuple/iterable of rational
numbers. The coordinates of the point.
OUTPUT:
Boolean.
EXAMPLES::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: line = LatticePolytope_PPL((1,2,3), (-1,-2,-3))
sage: line.contains([0,0,0])
True
sage: line.contains([1,0,0])
False
"""
p = C_Polyhedron(point(Linear_Expression(list(point_coordinates), 1)))
is_included = Poly_Con_Relation.is_included()
for c in self.constraints():
if not p.relation_with(c).implies(is_included):
return False
return True
def has_IP_property(self):
"""
Whether the lattice polytope has the IP property.
That is, the polytope is full-dimensional and the origin is a
interior point not on the boundary.
OUTPUT:
Boolean.
EXAMPLES::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: LatticePolytope_PPL((-1,-1),(0,1),(1,0)).has_IP_property()
True
sage: LatticePolytope_PPL((-1,-1),(1,1)).has_IP_property()
False
"""
origin = C_Polyhedron(point(0*Variable(self.space_dimension())))
is_included = Poly_Con_Relation.is_included()
saturates = Poly_Con_Relation.saturates()
for c in self.constraints():
rel = origin.relation_with(c)
if (not rel.implies(is_included)) or rel.implies(saturates):
return False
return True
def contains(self, point_coordinates):
r"""
Test whether point is contained in the polytope.
INPUT:
- ``point_coordinates`` -- a list/tuple/iterable of rational
numbers. The coordinates of the point.
OUTPUT:
Boolean.
EXAMPLES::
sage: from sage.geometry.polyhedron.ppl_lattice_polytope import LatticePolytope_PPL
sage: line = LatticePolytope_PPL((1,2,3), (-1,-2,-3))
sage: line.contains([0,0,0])
True
sage: line.contains([1,0,0])
False
"""
p = C_Polyhedron(point(Linear_Expression(list(point_coordinates), 1)))
is_included = Poly_Con_Relation.is_included()
for c in self.constraints():
if not p.relation_with(c).implies(is_included):
return False
return True